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Carbon (C) sequestration in soil plays a crucial role in increasing soil quality through recommended management practices including applying organic amendments, following cropping patterns, fallow periods etc. This study aimed to assess the influence of rice-based cropping patterns on soil C and nutrient status in surface (0-15 cm) and sub-surface soil (15-30 cm). Soils of five rice-based cropping patterns [Boro (winter rice)-Fallow-Fallow, Boro-Fallow-Aman (monsoon rice), Boro-Fallow-Aman-Mustard, Boro-Aus (summer rice)-Aman, Vegetables-short Fallow-Aman] from farmers' fields of Mymensingh district in Bangladesh were collected. Bulk soils were physically fractionated into particulate organic matter (POM: >53 µm) and mineral associated OM (MOM: < 53 µm) to assess the organic C (OC) distribution. Bulk soils were analyzed for soil pH, electrical conductivity, soil texture, nutrients (OC, nitrogen (N), phosphorus (P), potassium (K) and sulphur (S)) contents. The results showed that all studied parameters varied significantly among the cropping patterns and soil depths. Surface soils contain higher amount of OC, N, P, K and S than sub-surface soils under all rice-based cropping patterns. Overall, relatively higher macronutrients (P, K, S) concentration was found in the cropping patterns with a greater number of crops compared to the patterns including fallow period. In contrast, OC and N were the highest in Boro-Fallow-Fallow field followed by Vegetables-short Fallow-Aman and the rest three patterns, which might correspond to less disturbance of soil. All the rice-based cropping patterns had noticeable proportion of MOM (presumably stable OC) than labile POM which indicates the capacity of paddy soils in sequestering OC in soils. However, this capacity can be influenced by the pattern and probably also by the management systems, e.g., tillage and nutrient managements. These findings revealed the necessity of paying more attention to the selection of cropping pattern and proper land/or crop management for higher C sequestration in arable soil. [Fundam Appl Agric 2024; 9(3.000): 186-194]

Tank-mixture of two or more chemical groups of either pre- or post-emergence herbicide might play a vital role to manage weeds of a diversified community more effectively than their single or sequential application. Although some proprietary herbicides are available in the market, their number is very limited. The aim of this research was to evaluate the weed response to different tank-mix pre- or post- emergence herbicide combinations and its impact on winter rice performance in zero-till non puddled transplanted condition. Twenty-one treatments were used in each experiment (either pre- or post-emergence herbicide). Treatments comprised six pre-emergence herbicides with their 13 tank-mix combinations (at a ratio of 1:1), one proprietary pre-emergence herbicide and a season-long weedy plot as control. Similar treatments combination was also considered for post-emergence herbicide. Both the experiments were conducted under RCB design with three replications. Sole application of Triafamone pre-emergence herbicide performed as the best in terms of weed control efficiency (%) and yield increase over control (%) followed by Triafamone + Pretilachlor and Triafamone + Pendimethalin. In case of tank-mix post-emergence herbicide Pyrazosulfuron-ethyl+ Penoxsulam performed as the best in terms of weed control efficiency (%) and yield increase over control (%) followed by sole application of post-emergence Penoxsulam. Tank-mixture of Triafamone + Pretilachlor or Triafamone + Pendimethalin pre-emergence herbicide or Pyrazosulfuron-ethyl+ Penoxsulam post-emergence herbicide at a ratio of 1:1 might be the perfect alternative to sole or sequential application of herbicide for effective weed control and to obtain higher rice yield. [Fundam Appl Agric 2024; 9(3.000): 220-231]

This experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the varietal response of split application of NPK fertilizer application schedule on transplant aman rice under zero till non-puddled condition. The experiment comprised three rice varieties viz. Bashiraj (local), BRRI dhan49 (inbred), Dhanigold (hybrid); and seven NPK fertilizer application schedules. The experiment was laid out in a randomized complete block design with three replications. The effect of variety, NPK fertilizer split application schedule and their interaction showed significant variation on the yield attributes and yield of aman rice. In interaction, the highest number of effective tillers hill-1 (11.66), total spikelets panicle-1 (164.00), grains panicle-1 (151.22), 1000-grain weight (38.70 g), grain yield (5.67 t ha-1) and harvest index (60.36%) were obtained from hybrid variety Dhanigold when fertilized following 3-splits of N [1/3 at 14 days after transplanting (DAT) + 1/3 at maximum tillering (MT)+ 1/3 at panicle initiation (PI)] and P (1/3 as basal + 1/3 at MT + 1/3 at PI ), and single split of K as basal (full dose). Same treatment combination also provides the highest yield of BRRI dhan49, but the local Bashiraj gave the highest yield at recommended practice where only N was top-dressed at 3 splits. Based on this result, it may be concluded that for better productivity hybrid Dhanigold and inbred BRRI dhan49 might be fertilized with 3-splits of N (1/3 at 14 DAT + 1/3 at MT + 1/3 at PI) and P (1/3 as basal + 1/3 at MT + 1/3 at PI) and full dose of K as basal during aman season under zero till non-puddled condition. On the other hand, for local variety Bashiraj 3-spilts of N either [½ as basal + ¼ at active tillering (AT) + ¼ at PI] or N (1/3 at 7 DAT + 1/3 at MT + 1/3 at PI) and P, K as single split as basal appeared as the best application schedule. [Fundam Appl Agric 2024; 9(3.000): 153-161]

In a lab experiment using seed priming, the faba bean (Vicia faba L.) seed germination and seedling development were studied. Twenty different priming techniques were utilized in the study, each comprising varying concentrations of NaOCI, CaCl2, KNO3, Manitol, PEG, KCL, H2O and a control group that received no priming. Four replications of a completely randomized design (CRD) were used in the experiment. Among the three priming treatments, there were substantial differences in the seedling growth metrics and germination rate. When 500 ppm NaOCl was used as a treatment, the highest seed germination percentage (96%) was attained. Although 100 ppm PEG had the greatest germination index (42.92), 10000 ppm NaOCl had the quickest mean germination time (8.27). Additionally, at a concentration of 1500 ppm NaOCl, the greatest seedling vigor index (29.79) and maximum germination coefficient (12.28) were likewise obtained. With H2O treatment, the maximum shoot length (21.09 cm) was observed for seedling growth parameters. The largest root length was produced by a 10000 ppm KNO3 treatment (11.19 cm). With 20000 ppm KNO3, the maximum root dry weight was achieved (88.50 mg), whereas H2O produced the highest shoot dry weight (51.0 mg). Additionally, it was discovered that a treatment with 10000 ppm KNO3 had the best root-shoot ratio (0.72). The research thus supports the possible use of seed priming as a method to improve faba bean seed germination and seedling growth. NaOCl and KNO3 seemed to work best for faba bean seed germination and seedling growth.

To examine the impact of mixture ratio and temporal deployment of fine and coarse grain cultivars on rice productivity and profitability, two experiments were carried out at Bangladesh Agricultural University. In both investigations, two monsoon rice cultivars viz., Binadhan-13 (a tall, late-maturing, fine-grained) and Dhani Gold (a semi-dwarf, mid-maturing, coarse-grained) were utilized. In the 1st experiment, rice cultivars were planted in different mixture ratios viz., sole Binadhan-13, sole Dhani Gold, 1:1, 2:3, 3:2, 2:4 and 4:2 ratio of Binadhan-13 to Dhani Gold. The second study included the introducing time of Dhani Gold viz., seven days before or after or same day of Binadhan-13, sole Binadhan-13 and sole Dhani Gold. Three replications of the randomized complete block design were used for both trials. In the first experiment, both cultivars produced more when grown in mixtures as opposed to solitary cultures. Even though Dhani Gold's sole culture had the greatest yield, it was statistically equivalent to combined yields when Binadhan-13 and Dhani Gold were grown together in mixtures at 2:1, 3:1, or 4:1 ratios. The maximum net return and benefit cost ratio (BCR) were achieved when Binadhan-13 and Dhani Gold were planted in mixture following a 4:2 ratio as opposed to when Binadhan-13 was grown solely. In the second experiment, a sole cultivar generated less yield than cultivars that were transplanted on the same day, before, and after another cultivar. Cultivation of sole Binadhan-13 produced the lowest net return and minimum BCR (1.37), while the highest net return and BCR (1.81) was recorded when Dhani Gold was planted seven days before Binadhan-13 in mixture. A clear economic advantage of mixed culture with temporal deployment over the sole culture of either cultivar was evident. Therefore, transplanting Dhani Gold in a 1:1 ratio seven days before Binadhan-13 may be advised for greater output and economic return.

Millets are small-grained nutritious minor cereal crops that are resistant to different abiotic stresses resulting from climate change. Despite their many benefits, millets have received limited attention in agricultural research, policies, and markets. Considering the importance of millets, recently the government many tropical countries including India and Bangladesh give more emphasis to millets cultivation and improvement. Moreover, Food and Agricultural Organization of the United Nations (FAO) declared 2023 to be the “International Years of Millets”. In these connections, a details and updated review of the pros and cons of millets cultivation and its improvement in this region warrant due attention. The review therefore, examines the potential and main barriers to the adoption and promotion of millet cultivation in this region. These include limited research and development efforts, inadequate infrastructure and inputs, weak market linkages and demand, and insufficient awareness and knowledge about millets' nutritional and environmental benefits. This review also highlighted the prospects and strategies for scaling up millet cultivation in this region especially in Bangladesh. These include increasing public and private investment in research and extension services, strengthening farmers' organizations and market linkages, promoting millet-based value chains and products, and integrating millets into nation’s food policy. The review concludes that millets might support equitable and sustainable agricultural growth, which would contribute to global food and nutritional security and could help attain the sustainable development goals (SDGs). However, achieving this potential will require concerted efforts from multiple stakeholders, including farmers, researchers and policymakers. The review emphasizes the need for a multi-disciplinary and multi-stakeholder approach that prioritizes innovation, inclusiveness, and sustainability. Lastly, the review highlights more investigation into the socioeconomic, environmental, and nutritional effects of millet production in this region with special emphasis on Bangladesh in order to support evidence-based policies and practices.

This study aimed to ascertain the effect of land uses (cropland, orchard, grassland, and fallow) on soil OC pools in two depths (0–10 and 40–50 cm). Particulate organic matter (POM) (> 53 µm) and mineral associated OM (MOM) (< 53 µm) pools were physically separated from bulk soils and analyzed for OC and N analysis. For both depths, the soil from grassland showed considerably higher OC (0.96-1.47%) and N (0.084-0.095%) values than the other land uses. In surface depth, the lowest OC was found in cropland soil (0.83%) and in sub-surface, it was in fallow land soil (0.75%), whereas the orchard soil had moderate OC in both depths. Depth showed significant differences in OC distribution. Surface soils had higher OC than the sub-surface soils which can be explained by the continuous addition of organic residues (crop/leaf/dried grasses) on the top soil. The distribution of POM and MOM fractions among the soils of different land uses were different. Interestingly, cropland and orchard soils had higher MOM-OC (MOC) than POM-OC (POC) in comparison to the relatively less disturbed grassland and fallow land soils. The amount of OC and N in OM pools was significantly different among the land uses in both depths. In surface depth, cropland soil showed the lowest POC content whereas the orchard and fallow land soils showed relatively higher. The MOC content was highest in fallow land (2.73%), lowest in orchard (1.30%) and cropland had moderate amount. In sub-surface depth, amount of OC was higher than surface soils and the trend of OC distribution between POM and MOM was different. Grassland soil had the highest OC (2.89-3.10%) for both fractions, followed by cropland > orchard > fallow. These findings showed that in cropland disturbance in soil could aid in depleting OC only from the most labile POM pool keeping the OC almost intact in stable MOM pool. Less disturbance in native soil condition such as grassland does not always benefit in enhancing/maintaining OC, rather it depends on the quality and quantity of OM added in the soils from the vegetation cover. [Fundam Appl Agric 2023; 8(1.000): 483-489]

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the yield of boro rice influenced by transplanting systems and different weed management practices. The experiment comprised two transplanting systems viz., (ⅰ) puddled transplanted rice (PTR) and (ⅱ) zero till non-puddled transplanted rice (ZT-NPTR) and five weed management practices viz., (ⅰ) weedy, (ⅱ) weed free, (ⅲ) farmers' practice (3 manual weeding), (ⅳ) application of pre-emergence herbicide Pretilachlor, and (ⅴ) application of post-emergence herbicide Penoxsulam. The experiment was laid out in randomized complete block design with three replications. Twelve weed species belonging to four families infested the experimental plots. Transplanting systems and weed management practices exerted significant influence on yield attributes and yield of boro rice. At 60 days after transplanting (DAT), maximum weed dry biomass (184.11 g m-2) was found in weedy practices of ZT-NPTR, while the highest weed density (143 no. m-2) was obtained from the weedy plots of PTR. The highest number of effective tillers hill-1 (15.60), grains panicle-1 (125), 1000-grain weight (22.50g), grain (4.78 t ha-1) and straw (5.16 t ha-1) yield was obtained from the weed free plots of PTR. The grain yield was at par with pre- and post-emergence herbicide applied plots of PTR, and farmers' practice and post-emergence herbicide applied plots of ZT NPTR. The maximum gross return (185650 Tk. ha-1), net return (79833 Tk. ha-1) and BCR (1.75) were obtained from the application of post-emergence herbicide Penoxsulam in ZT-NPTR system compared to other practices. Although, maximum grain yield was obtained from PTR under weed free condition, in terms of both grain yield and economic view point ZT-NPTR with post-emergence herbicide application might be an alternative way for sustainable crop production and weed management practices. [Fundam Appl Agric 2023; 8(1.000): 497-506]

A key and ecologically sound strategy for integrated weed management is the use of varieties of weed-competitive crops. Utilizing wheat cultivars that are weed-competitive can lessen weed pressure and inordinate herbicide usage in wheat fields by a substantial amount. To assess the weed suppressibility of Bangladeshi wheat varieties, a field test was carried out in 2018 throughout the winter season at the Agronomy Field Laboratory, Bangladesh Agricultural University, Bangladesh. Tests on a total of 18 selected Bangladeshi wheat cultivars were conducted in both “weedy” and “weed-free” environments. Additionally, weed monoculture plots (without wheat) were kept. The experiment was replicated three times using a randomized complete block design (RCBD). The results demonstrated that wheat varieties' weed interference and production capabilities differed greatly. BARI Gom 22 permitted the most weed growth (35 m−2), whereas BARI Gom 23 allowed the least (15 m−2) at 60 DAS among the wheat types under study. Grain yield ranged between 4.42 t ha−1 (BARI Gom 20) and 5.45 t ha−1 (BARI Gom 26) in weed-free settings, whereas it fluctuated from 2.48 t ha−1 (BARI Gom 21) to 3.93 t ha−1(BARI Gom 33) in weedy condition. The extent of the relative yield loss brought on by weeds ranged from 24 to 53%, with BARI Gom 33 suffering the least and Binagom-1 suffering the most. The weed competitive index varied from 0.48 to 1.47 for the examined wheat types. Among the cultivars, Binagom-1 had the lowest WCI and BARI Gom 29 had the highest. Although BARI Gom 33 was the best yielder in weedy condition and had the lowest relative yield loss, its interference against weed was moderate. Relative to the other varieties under consideration, comparatively BARI Gom 33 was the best in terms of yield and weed interference, but it is also advocated that breeders should continually focus on developing a variety that has both excellent producing potential and robust weed suppression.

The need to meet food demand becomes more urgent as it is forecasted to increase by 50% over the next century. Thus, agronomists promote sensible tools and approaches to eradicate factors that hamper crop production, mainly weeds. The constant use of chemical herbicides to control weeds leads to an increased risk of herbicide-resistant weed populations, environmental pollution, unsafe agricultural products, and negative effects on human health. These problems have caused an interest among researchers to replace synthetic herbicides with alternatives. The purpose of this review was to present the current knowledge base on allelopathic tropical plants and their potential for use in the development of natural product-based, environmentally friendly herbicides for sustainable agriculture, and to stimulate future discussion on this topic. The defence mechanisms of tropical plants have received particular attention because of their potential weed control ability as a natural pesticide that can prevent the overuse of synthetic pesticides. The ancient knowledge of the toxic properties of various tropical plants gives us a basis for creating a novel pest control approach. The synthesis of biopesticides based on allelochemicals opens up the possibility of utilizing natural compounds in crop protection and demonstrates the ability to deal with evolved pesticide resistance.

As evident from the past, although pandemic is a health issue it could lead to food security and economic crises. Since agriculture accounts for more than 3.3% of global gross domestic product and 60% of the population depends on agriculture for their livelihoods, COVID-19 pandemic impact on agriculture may result in acute hunger and malnutrition, and the deepest global recession in recent history. Agriculture is experiencing a huge challenge in dealing with both supply and demand shocks. Globally, there is sufficient food to feed the people but the challenge is to make food available to everyone due to logistic bottlenecks and high price. The hard-won lessons from this pandemic is that feeding the world is always a challenging task and therefore we should search for a more resilient, sustainable and regenerative food production and supply system to cope with such a crisis. Prompt response and immediate acceleration are needed to support the recovery process and minimize deterioration. Agri-food sector must be reoriented so that it can function more effectively in the post COVID-19 era. [Fundam Appl Agric 2020; 5(3.000): 289-294]

Purpose: Aphanamixis polystachya (Wall.) R.N. Parker, belonging to Meliaceae family is very well known for its medicinal properties. But its allelopathic potentiality not yet has been reported. Hence, aqueous extracts of different parts of Aphanamixis polystachya were examined to investigate their allelopathic potentiality. Research Method: Different parts of A. polystachya extracts at four different concentrations (1:5, 1:10, 1:15 and 1:20 (w/v)) along with control (distilled water without extracts) were tested against jute, mungbean, mustard, radish, rice, wheat and tomato. The experiments were conducted following completely randomized design with three replicates. Findings: Among the test crop species, shoot growth of mustard was most sensitive (43% average inhibition (a.i.)) followed by radish (41% a.i.) to the extracts of different parts of A. polystachya., whereas shoot growth of tomato (14% a.i.) was less sensitive to the extracts followed by rice (25% a.i.) and mungbean (29% a.i.). Root growth of radish was most sensitive (41% a.i.) species followed by mustard (39% a.i.) and jute (36% a.i.) to the extract of different parts of A. polystachya. Root growth of mungbean (13% a.i.) was less sensitive to the extracts followed by tomato (18% a.i.) and rice (20% a.i.). Among the plant parts, leaf showed most phytotoxic activity on the shoot growth (41%) and twig on the root (40%) growth of the test plants. However, stem extract was less sensitive to both shoot and root growth of the test species. These results confirm that A. polystachyahas allelopathic properties and may possess allelochemicals. Research limitations: There was no significant limitation to the report. Originality/Value: To the best of our knowledge this is the first report about the allelopathic potential of Aphanamixis polystachya.

Timely sowing/planting of rabi crops in T. aman rice Rabi crop Boro rice pattern is very important. Short duration rice varieties are cultivated in aman season to facilitate timely sowing of rabi crops. Most of the short duration aman rice varieties are sensitive to early transplanting and thus, early vacating of land for subsequent rabi crops planting does not happen. This experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University to investigate the yield performance of some boro rice varieties in response to date of transplanting in aman season. Five rice varieties viz. BRRI dhan28, BRRI dhan48, BRRI dhan55, BRRI dhan58 and Binadhan-7 were transplanted at four dates viz. 21 June, 11 July, 1 August and 22 August 2016 in a split-plot design with three replications. The variety and date of transplanting had significant interaction effects on grain yield and most of the crop characters of rice. BRRI dhan58 produced the highest grain yield (5.45 t ha-1), straw yield (6.17 t ha-1), biological yield (11.62 t ha-1) with in the lowest field duration (96 days) among the different varieties transplanted at different dates. Short duration aman rice variety Binadhan-7 gave the highest yield of 5.10 t ha-1 when planted on 1 August and required field duration of 109 days while BRRI dhan48 gave the highest yield of 5.10 t ha-1 and required 107 days when transplanted on 22 August. The present study concludes that BRRI dhan58 could be used as a short duration rice variety for obtaining high yield in early aman season and for vacating the land for facilitating early sowing of rabi crops. [Fundam Appl Agric 2020; 5(1.000): 108-115]

This current investigation was undertaken both in laboratory and glasshouse for documentation and quantification of phytochemicals from different parts of the parthenium (Parthenium hysterophorus L.) plant through LC-MS and HPLC to study their effect on two crops namely, Bambara groundnut (Vigna subterranean L.) and maize (Zea mays L.), and six different types of weed e.g., Digitaria sanguinalis, Eleusine indica, Ageratum conyzoides, Cyperus iria, Euphorbia hirta, and Cyperus difformis. The parthenium methanolic leaf extracts at 25, 50, 75, and 100 g L−1 were sprayed in the test crops and weeds to assess their physiological and biochemical reactions after 6, 24, 48, and 72 h of spraying these compounds (HAS). The LC-MS analysis confirmed seven types of phytochemicals (caffeic acid, ferulic acid, vanillic acid, parthenin, chlorogenic acid, quinic acid, and p-anisic acid) in the parthenium leaf extract that were responsible for the inhibition of tested crops and weeds. From the HPLC analysis, higher amounts in leaf methanol extracts (40,752.52 ppm) than those of the stem (2664.09 ppm) and flower extracts (30,454.33 ppm) were recorded. Parthenium leaf extract at 100 g L−1 had observed higher phytotoxicity on all weed species except C. difformis. However, all crops were found safe under this dose of extraction. Although both crops were also affected to some extent, they could recover from the stress after a few days. The photosynthetic rate, transpiration rate, stomatal conductance, carotenoid and chlorophyll content were decreased due to the application of parthenium leaf extract. However, when parthenium leaf extract was applied at 100 g L−1 for 72 h, the malondialdehyde (MDA) and proline content were increased in all weeds. Enzymatic antioxidant activity (e.g., superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) contents) were also elevated as a result of the sprayed parthenium leaf extract. The negative impact of physiological and biochemical responses as a consequence of the parthenium leaf extract led the weed species to be stressed and finally killed. The current findings show the feasibility of developing bioherbicide from the methanolic extract of parthenium leaf for controlling weeds, which will be cost-effective, sustainable, and environment friendly for crop production during the future changing climate.

Highly diversified tropical tree species could be a potential source of allelopathic compounds, which could lead to development of natural bio-herbicides for sustainable weed management. The present study was therefore designed to investigate into the allelopathic potential of sawdust obtained from eleven tropical tree species available in Bangladesh viz., Azadirachta indica, Swietenia macrophylla, Acacia auriculiformis, Tamarindus indica, Eucalyptus camaldulensis, Syzygium cumini, Mangifera. indica, Albizia. saman, Artocarpus. heterophyllus, Diospyros discolor and Tectona grandis. The aqueous sawdust extract of these plant species were diluted into four different concentrations viz. 1:5, 1:10, 1:15, 1:20 (w/v) and tested for their potentiality in inhibiting seedling growth of allelopathic sensitive plant Raphanus sativus under laboratory condition. A control (distilled water without extract) was also maintained in every cases and the bioassay experiment was replicated thrice. The results of this experiment showed that S. macrophylla, E. camaldulensis, M. indica and A. saman inhibited more than 90% shoot and root growth of R. sativus. The sawdust of these four plant species were selected to evaluate their potentiality in controlling paddy field weeds under filed condition. A total of 16 weed control treatments were considered in the field experiment viz., sawdust of selected four tree plant species at three application rates (1, 2 and 3 t ha-1), manual weeding (three times), chemical control (pre- + post- emergence herbicides), chemical + manual control and season long weedy (control). The results showed that the effect of different sawdust on the weed control varied significantly. Weed growth suppression by the sawdust was increased with the increase in application rate. The results revealed that manual, chemical weed control and application of E. camaldulensis saw dust @ 3 t ha-1 reduced the weed density by 79, 77 and 72%, respectively, and weed biomass by 86, 84 and 79%, respectively. On the other hand, manual weed control offered 100% rice yield increase while, chemical control and E. camaldulensis saw dust @ 3 t ha-1 both resulted in 92% rice yield increase over control. Although, manual and chemical weed control offered higher weed control efficiency and resulted in better rice productivity, but from environmental viewpoint application of E. camaldulensis sawdust @ 3 t ha-1 may be considered for sustainable weed management in rice. [Fundam Appl Agric 2019; 4(3.000): 906-915]

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during July to December 2016 to find out the effect of age of seedlings and level of nitrogen on the growth and yield of transplant Aman rice cv. Binadhan-16. The experiment comprised four ages of seedlings viz. 15, 20, 25 and 30-day old and four levels of nitrogen viz. 0, 50, 70 and 90 kg N ha-1. The experiment was laid out in a randomized complete block design (RCBD) with three replications. The results revealed that the effect of age of seedlings and level of nitrogen and their interaction was significant on yield and yield contributing characters of transplant Aman rice. The highest plant height and total dry matter production hill-1 were recorded in the treatment of 15-day old seedlings with 70 kg N ha-1. Grain yield gradually increased with the use of relatively younger seedlings and with 15-day old seedlings produced the highest values of effective tillers hill-1 (8.583), grains panicle-1 (122.7), grain yield (4.265 t ha-1) and straw yield (5.392 t ha-1). In case of level of nitrogen, 70 kg N ha-1 produced the highest grains panicle-1 (114.1), grain yield (4.539 t ha-1) and straw yield (5.623 t ha-1). In interaction, 15-day old seedlings with 70 kg N ha-1 produced the highest effective tillers hill-1 (9.71), grain yield (5.17 t ha-1) and straw yield (6.20 t ha-1). Therefore, 15-day old seedlings with 70 kg N ha-1 appeared as the promising technique to obtain the highest grain yield [Fundam Appl Agric 2019; 4(2.000): 785-791]

The utilization of the invasive weed, Parthenium hysterophorus L. for producing value-added products is novel research for sustaining our environment. Therefore, the current study aims to document the phytotoxic compounds contained in the leaf of parthenium and to examine the phytotoxic effects of all those phytochemicals on the seed sprouting and growth of Crabgrass Digitaria sanguinalis (L.) Scop. and Goosegrass Eleusine indica (L.) Gaertn. The phytotoxic substances of the methanol extract of the P. hysterophorus leaf were analyzed by LC-ESI-QTOF-MS=MS. From the LC-MS study, many compounds, such as terpenoids, flavonoids, amino acids, pseudo guaianolides, and carbohydrate and phenolic acids, were identified. Among them, seven potential phytotoxic compounds (i.e., caffeic acid, vanillic acid, ferulic acid, chlorogenic acid, quinic acid, anisic acid, and parthenin) were documented, those are responsible for plant growth inhibition. The concentration needed to reach 50% growth inhibition in respect to germination (ECg50), root length (ECr50), and shoot length (ECs50) was estimated and the severity of phytotoxicity of the biochemicals was determined by the pooled values (rank value) of three inhibition parameters. The highest growth inhibition was demarcated by caffeic acid, which was confirmed and indicated by cluster analysis and principal component analysis (PCA). In the case of D. sanguinalis, the germination was reduced by 60.02%, root length was reduced by 76.49%, and shoot length was reduced by 71.14% when the chemical was applied at 800 μM concentration, but in the case of E. indica, 100% reduction of seed germination, root length, and shoot length reduction occurred at the same concentration. The lowest rank value was observed from caffeic acids in both E. indica (rank value 684.7) and D. sanguinalis (909.5) caused by parthenin. It means that caffeic acid showed the highest phytotoxicity. As a result, there is a significant chance that the parthenium weed will be used to create bioherbicides in the future.

Herbicide resistance due to the increasing reliance on herbicides is a near-term challenge for the world’s agriculture. This has led to a desire to develop new herbicides with a novel mode of action, to address resistance in weed species. Lamiaceae, a large dicotyledonous plant family, is very well known for the multitudinous pharmacological and toxicological properties of its member species. Moreover, many species of this family are significant for their allelopathic activity in natural and laboratory settings. Thus, plants in Lamiaceae have the potential to be sources of alternative herbicides. However, gaps in our knowledge need to be addressed prior to adopting these allelopathic activities in agriculture. Therefore, we review the existing state of knowledge about the Lamiaceae family, the reported allelopathic properties of plant extracts, and their isolated allelochemicals under laboratory, greenhouse, and field conditions. In addition, we offer a perspective on existing challenges and future opportunities for adopting the allelopathic properties of Lamiaceae plant species for green agriculture.

The current research was conducted to investigate the allelopathic properties of 55 medicinal plant species of Bangladesh representing 32 different families. The aqueous leaves or whole plant extract of those plant species was diluted into four different concentrations viz., 1:5, 1:10, 1:15, 1:20 (w/v) and tested against the seedling growth of Raphanus sativus. A control (distilled water without extract) was also maintained in every cases and the bioassay experiment was replicated thrice. The aqueous extract of all these species inhibited both shoot and root length of R. sativus at concentration greater than 1:15 (w/v) except Delonix regia (Fabaceae) and Leucas aspera (Lamiaceae). The inhibitory activity was concentration dependent and root growth was more sensitive than their shoot. Among the plant species, Citrus aurantifolia (Rotaceae), Moringa oleifera (Moringaceae), Annona muricata (Annonaceae), Aegle marmelos (Rutaceae), Cinnamomum tamala (Lauraceae) and Azadirachta indica (Meliaceae) completely (100%) inhibited the shoot and root growth of R. sativus at concentration 1:5 (w/v). Other than this six plant species, 15 out of 49 medicinal plants showed more than 95% shoot and root growth inhibition at the same concentration. The least allelopathic potential plant was Garcinia mangostana (Clusiaceae) that showed on an average 36% growth inhibition followed by Schleichera oleosa (Sapindaceae). Based on these results it can be concluded that among the tested plant species, C. aurantifolia, M. oleifera, A. muricata, A. marmelos, C. tamala, and A. indica are strongly allelopathic and therefore, could be used as potential candidates for the development of eco-friendly natural herbicides. Keywords: Medicinal plants, Tropical plants, Bio-herbicide, Eco-friendly, Sustainable agriculture

Over dependence on chemical fertilizers is a threat to the sustainability of rice ecosystem. Application of organic and biofertilizers might reduce reliance on chemical fertilizers and thus can play a vital role to boost up rice productivity in an eco-friendly way. An experiment was conducted at Mymensingh (24°10'0'' N latitude and 90°25'0" E longitude at 15 m above the sea level), Bangladesh during November 2015 to April 2016 to evaluate the effect of different dosages of Agroplus Biodecomposer, an organic biofertilizer containing Streptomycetes bacteria, on the growth and yield performance of some rice. The experiment included four winter rice varieties viz. (i) Hybrid rice Hira and (ii) Hybrid rice Tej (iii) BRRI dhan28 and (iv) BRRI dhan29; and four concentrations of Agroplus Biodecomposer viz. (i) no Agroplus Biodecomposer (Control), (ii) 2% Agroplus Biodecomposer (iii) 3% Agroplus Biodecomposer and (iv) 4% Agroplus Biodecomposer. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Agroplus Biodecomposer positively influenced growth and productivity of winter rice. It was evident that both plant height and tillering ability of winter rice were increased gradually with increased concentration of Agroplus Biodecomposer at all the growth stages of rice. All the yield contributing characters of rice were enhanced due to Agroplus Biodecomposer application which resulted in increased grain yield. Compared to control, rice grain yield was increased by 14, 20 and 28%, respectively due to application of Agroplus Biodecomposer at 2, 3 and 4% concentration. Rice variety also differed significantly in terms of growth and yield performance among themselves. Hybrid varieties performed better than inbred ones. Hybrid variety Hira appeared as the best performer followed by another hybrid Tej. Hybrid variety Hira interacted favorably with 4% Agroplus Biodecomposer to produce the highest grain yield of rice (7 t ha-1). Therefore, biofertilizer Agroplus Biodecomposer can be introduced to Bangladesh and foliar spray with 4% Agroplus Biodecomposer at 30, 45 and 60 DAT can be recommended for boosting up winter rice yield in a sustainable way. [Fundam Appl Agric 2018; 3(1.000): 372-381]

Abiotic stresses varyingly affect the grain composition and quality of food legumes. This paper is aimed at discussing the impact of abiotic stresses on the grain composition and quality of food legumes. As protein is the main grain constituent of food legumes for which it is being consumed by humans as a cheap protein source, abiotic stresses such as heat, cold, drought, salinity and heavy metals alter this grain protein content in different dimensions for different food legumes. Moreover, other valuable constituents such as starch, soluble sugar, oil, fatty acid and fiber content are affected differently by the abiotic stresses. The diverse impact of these abiotic stresses ultimately declines the grain quality and yield of food legumes. As food legumes play a vital role in the nutritional diet of millions of people in the world and are occasionally denoted as the meat of poor people, it is important to recognize that the sustainable production of food legumes, even under various environmental stresses, has the potential to ensure protein security for people globally. Therefore, it has become a necessity to improve the productivity and quality of food legumes under abiotic stresses through proper crop management and improved breeding strategies, thus enhancing food and economic security to the farmers, particularly in the developing countries of the world.

Grain legumes are important sources of proteins, essential micronutrients and vitamins and for human nutrition. Climate change, including drought, is a severe threat to grain legume production throughout the world. In this review, the morpho-physiological, physio-biochemical and molecular levels of drought stress in legumes are described. Moreover, different tolerance mechanisms, such as the morphological, physio-biochemical and molecular mechanisms of legumes, are also reviewed. Moreover, various management approaches for mitigating the drought stress effects in grain legumes are assessed. Reduced leaf area, shoot and root growth, chlorophyll content, stomatal conductance, CO2 influx, nutrient uptake and translocation, and water-use efficiency (WUE) ultimately affect legume yields. The yield loss of grain legumes varies from species to species, even variety to variety within a species, depending upon the severity of drought stress and several other factors, such as phenology, soil textures and agro-climatic conditions. Closure of stomata leads to an increase in leaf temperature by reducing the transpiration rate, and, so, the legume plant faces another stress under drought stress. The biosynthesis of reactive oxygen species (ROS) is the most detrimental effect of drought stress. Legumes can adapt to the drought stress by changing their morphology, physiology and molecular mechanism. Improved root system architecture (RSA), reduced number and size of leaves, stress-induced phytohormone, stomatal closure, antioxidant defense system, solute accumulation (e.g., proline) and altered gene expression play a crucial role in drought tolerance. Several agronomic, breeding both conventional and molecular, biotechnological approaches are used as management practices for developing a drought-tolerant legume without affecting crop yield. Exogenous application of plant-growth regulators (PGRs), osmoprotectants and inoculation by Rhizobacteria and arbuscular mycorrhizal fungi promotes drought tolerance in legumes. Genome-wide association studies (GWASs), genomic selection (GS), marker-assisted selection (MAS), OMICS-based technology and CRISPR/Cas9 make the breeding work easy and save time in the developmental cycle to get resistant legumes. Several drought-resistant grain legumes, such as the chickpea, faba bean, common bean and pigeon pea, were developed by different institutions. Drought-tolerant transgenic legumes, for example, chickpeas, are developed by introgressing desired genes through breeding and biotechnological approaches. Several quantitative trait loci (QTLs), candidate genes occupying drought-tolerant traits, are identified from a variety of grain legumes, but not all are under proper implementation. Hence, more research should be conducted to improve the drought-tolerant traits of grain legumes for avoiding losses during drought.

Crop production is a constant battle with weeds, in which weeds, generally, are victorious. Therefore, rather than channeling our efforts into the development of a “silver bullet” to control weeds, the focus should be on sustainable weed management in both natural- and agro-ecosystems. However, sustainable weed management can be a challenge in the context of global climate change. Over the past few decades, global climate change, mostly indicated by phenomena such as increased atmospheric temperature and elevated CO2 levels, is evident due to human activities and natural events. These phenomena also affect regional/local climate, resulting in significant influences on the agricultural systems of a particular region. Rising CO2 levels may give comparative advantages to C3 plants through increased photosynthesis, biomass production and yield, compared to C4 plants. Plants with C4 photosynthetic pathways, on the other hand, are likely to benefit more from rising global temperatures than C3 plants. Thus, the differential responses of C3 and C4 plants to climate change may alter crop–weed interactions and competition outcomes, most likely at the expense of the crop. Climate change will likely cause shifts in weed community compositions, their population dynamics, life cycle, phenology, and infestation pressure. Some weed species may go extinct, while some others may become more aggressive invaders. Weeds are, generally, colonizers and have some unique biological traits and ecological amplitudes that enable them to successfully dominate crops in a habitat with changed environmental conditions. Moreover, climate shifts, especially erratic rainfall and drought, may affect herbicide selectivity and efficacy or the success of bio-control agents resulting in an establishment of a mixed and complex population of C3 and C4 weed species adding to the complexity of weed management. Although elevated CO2 levels will stimulate the productivity of major C3 crops, most troublesome agricultural weeds will likely be more responsive to a rise in CO2 than crops, and thus may dominate the agro-ecosystem. It is predicted that, as temperature rises, the majority of the C4 weeds will flourish and will pose serious crop yield losses. Understanding and assessment of the impact of simultaneous changes in multiple climate factors and their complex interactions on crops and weeds are therefore necessary to formulate an adaptive weed management approach and build resilience. Moreover, strategic policies and strong actions need to be taken to reduce the root causes of CO2 and other greenhouse gas emissions to minimize the impact of climate change on weed biology and management.

Plant spacing and weeding regime are amongst the key factors determining rice growth and yield through maximum utilization of space, plant nutrients, water and sunlight. Therefore, it is essential to identify optimum spacing and proper weeding regime for ensuring the potential yield of a rice cultivar. A field experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh during July- December 2012 to study the influence of spacing and weeding regime on the performance of transplant aman rice cv. Binadhan-7. The experiment comprised four plant spacings viz. 25 cm × 15 cm, 20 cm × 15 cm, 15 cm × 15 cm and 15 cm × 10 cm, and five weeding regimes viz. no weeding, one weeding at 15 days after transplanting (DAT), two weeding at 15 and 30 DAT, three weeding at 15, 30 and 45 DAT and weed free. The experiment was laid out in a randomized complete block design (RCBD) with three replications. The highest weed density and dry weight were recorded with the spacing of 20 cm × 15 cm and 25 cm × 15 cm, respectively. But the lowest values were observed in the closest spacing of 15 cm × 10 cm. Plant spacing exerted significant influence on most of the plant characters except plant height and 1000-grain weight. The highest and statistically significant grain yield was obtained from 20 cm × 15 cm spacing (6.05 t ha-1) and 25 cm × 15 cm spacing (6.04 t ha-1) because of highest number of filled grains panicle-1 (143.65) and highest number of effective tillers hill-1 (10.13). Weeding regime also had significant effect on all the parameters except 1000-grain weight. The highest grain yield (6.29 t ha-1) was obtained from the weed free condition which produced 37.33% higher yield than unweeded condition (4.58 t ha-1). Interaction between plant spacing and weeding regime significantly influenced all the parameters studied except 1000-grain weight. The highest grain yield (6.71 t ha-1) was obtained from the interaction between 20 cm x 15 cm spacing and three weeding regimes at 15, 30, 45 DAT which was similar to the treatment combination of 15 cm × 15 cm spacing and weed free condition. But maintaining season long weed free condition is not practical from economic view point, therefore Binadhan7 should be transplanted at 20 cm × 15 cm spacing following three times weeding at 15, 30 and 45 DAT for higher yield and effective weed control. [Fundam Appl Agric 2017; 2(3.000): 331-339]

This study aimed to determine the impact of land use on organic carbon (OC) pools of soils with contrasting native organic matter (OM) content. Surface (0–15 cm) soils of four land uses (cropland, orchard, grassland, and fallow) were collected from four agroecological zones (AEZs) of Bangladesh with different OM content (AEZ-7: very low, −3: low, −9: medium, and −5: high). Bulk soils were physically fractionated into particulate and mineral associated OM (POM and MOM: >53 and

Parthenium hysterophorus is an invasive weed species that competes aggressively with other plants and is also allelopathic. It poses a significant risk to human health, livestock, the environment, soil, and agriculture. However, given some clinical studies, its potential for antidiabetic, antioxidant, antitumor, herbicidal, pesticidal, and antimalarial therapies should be researched further in attempts to discover more relevant applications. It can be used as a nutrient-dense, readily available, and cheap fertilizer. Parthenium can also be used as an herbicide, an insecticide, and a phyto-remedial mediator to extract metals and dyes from agricultural waste. Here we provide basic information on the morphology, reproduction, environmental impacts, and management of this species. Effects of methanol, ethanol, hexane, acetone, and aqueous (water) Parthenium extracts are described. Because P. hysterophorus is said to be one of the world’s seven worst weeds, some control measures, including mechanical, chemical, cultural, and biological control, are discussed. The allelopathy of this weed is difficult to regulate, and there are both positive and negative interactions between Parthenium and other species due to allelochemical action. Several toxic phenolic compounds produced by P. hysterophorus are responsible for weed suppression, and we discuss details of their mode of action and potential applications.